This invention pertains to counters which can be incremented by different values. In the above-cited application there is disclosed a system for displaying lines of text on a horizontal raster-scanned cathode-ray display. The lines of text are stored in a memory and are called as need. The system can display such characters in a normal mode or a magnified mode when the characters are displayed at twice the height of the normal mode. This is accomplished by switching the raster between sequential and interlaced modes. Such a technique can utilize a counter which can be switched between unit incrementing and double incrementing. Such counters are known from U.S. Pat. No. 3,742,482. However, when such systems are in the interlaced mode, the counter should count in one field by odd numbers and in another field by even numbers.